Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submissions filed on 04/22/2026 and 6/16/2026 have been entered.
DETAILED ACTION
The supplemental amendment filed 06/16/2026 is acknowledged. Claims 9, 13-14 and 16 are canceled. Claims 1-8, 10-12, 15 and 17-18 are pending and under consideration.
Priority
The instant claims are entitled to an effective filing date of 03/30/2022.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-8, 10-12, 15 and 17-18 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for a method of producing gamma-butyrolactone (GBL) product from a starting biomass containing water and genetically engineered E. coli cells designed to yield poly-4-hydroxybutyrate (P4HB) from glucose syrup as a carbon feed source, the method comprising: (a) introducing the starting biomass to an evaporator, (b) introducing liquid or vapor GBL to the evaporator as a solvent in a weight equivalent to or less than a weight of water removed to obtain a biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and comprises P4HB dissolved or suspended in the GBL, (c) combining, in a reaction vessel, the biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and a sodium carbonate or calcium hydroxide conversion catalyst and heating the resulting mixture to convert the P4HB to GBL, and (d) collecting the GBL, wherein the liquid or vapor GBL introduced in step (b) is a recycle GBL that is a part of the collected GBL obtained in step (d) and recycled back to the evaporator to be mixed as a solvent with the biomass, wherein the method does not include spray drying and drum drying, wherein the starting biomass is a genetically engineered biomass from a host cell that includes a non-naturally occurring amount of P4HB, and wherein a content of P4HB, and wherein a content of P4HB in the starting biomass is greater than 10% by weight of the total starting biomass.
The specification does not reasonably provide enablement for a method of producing GBL product from a starting biomass containing water and P4HB-containing cells, the method comprising: (a) introducing the starting biomass to an evaporator, (b) introducing liquid or vapor GBL to the evaporator as a solvent in a weight equivalent to or less than a weight of water removed to obtain a biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and comprises P4HB dissolved or suspended in the GBL, (c) combining, in a reaction vessel, the biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and a sodium carbonate or calcium hydroxide conversion catalyst and heating the resulting mixture to convert the P4HB to GBL, and (d) collecting the GBL, wherein the liquid or vapor GBL introduced in step (b) is a recycle GBL that is a part of the collected GBL obtained in step (d) and recycled back to the evaporator to be mixed as a solvent with the biomass, wherein the method does not include spray drying and drum drying. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the invention commensurate in scope with these claims.
The factors to be considered in determining whether a disclosure would require undue experimentation include:
A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
In re Wands, 8 USPQ2d, 1400 (CAFC 1988) and MPEP 2164.01.
The breadth of the claims and the nature of the invention:
Under the broadest reasonable interpretation, the claims are drawn to a method of producing GBL from a starting biomass containing water and any cell containing P4HB, the method comprising: (a) introducing the starting biomass to an evaporator, (b) introducing recycled liquid or vapor GBL to the evaporator in a weight equivalent to or less than a weight of water removed in order to obtain a biomass suspension or solution that comprises P4HB in GBL, (c) combining that biomass suspension or solution with any compound that can serve as a catalyst in the presence of heat to convert P4HB to GBL, and (d) collecting the GBL, and wherein the method does not include spray drying and drum drying.
The claims require the starting biomass to be a genetically engineered biomass from a host cell that includes a non-naturally occurring amount of P4HB. Yet, the genetic modification is not limited in anyway. As such, the starting biomass encompasses a breadth of genetic mutations.
The state of the prior art and the level of predictability in the art:
With respect to the state of the art on P4HB-containing cells, Mitra (Molecules, 2021, 26(23), 7244) suggests that researchers are continuously engrossed in developing various strategies to realize P4HB synthesis in microbes. See the first paragraph on page 2. Mitra discloses that E. coli can produce P4HB using glucose if it is genetically modified to express a phaCAB gene cluster and phaP1 gene from C. necator, and orfZ-sucD-4hbD from C. kluyveri; and genetically modified to knock out the sad and gabD genes. Moreover, E. coli can produce P4HB using xylose and 4-hydroxybutyric acid as substrates, or using glycerol and propionic acid as substrates if it is genetically modified to express phaC from C. necator and orfZ from C. kluyveri. See table 1. Mitra concludes that P4HB is a promising biomaterial in the biomedical field, however its synthesis is a constraint as most microbes lack 4HB synthesis pathways. See section 5. For GBL production, Peoples (US 2016/0068463), in example1, teaches producing a biomass containing P4HB using a genetically modified E. coli strain specifically designed for high yield production of P4HB from glucose syrup as the sole carbon feed source. The use of a renewable resource-based feedstock such as glucose syrup as the sole carbon source enables the production of a biobased P4HB and hence the production of biobased GBL and derivatives. The E. coli strain generates a fermentation broth that has a P4HB titer of approximately 100-120 g of P4HB/kg broth. After fermentation, the broth is washed and mixed with standard hydrated lime Ca(OH)--2. See [0175]. During pyrolysis the products of the thermal degradation of biomass+P4HB, GBL, is collected in a condensate trap. See [0178]. The GBL product yield (g of GBL product/ g of starting P4HB)x100) is approximately 87%. See [00179]. Thus, Mitra illustrates the breadth of P4HB containing cells and Peoples teaches producing biobased GBL with a specific P4HB containing cell.
The amount of direction provided by the inventor and the existence of working examples:
The instant specification provides one working example of a biomass containing P4HB. In example 1, a biomass containing P4HB is produced using a genetically modified E. coli strain specifically designed for high yield production of poly-4HB from glucose syrup as a carbon feed source. Examples of the E. coli strains, fermentation conditions, media and feed conditions are described in, for example, US 6,316,262 (as cited in the IDS filed 03/28/2023). After fermentation, a broth containing about 10% by weight of P4HB, 10% by weight of biomass and salts is obtained. See [0092]. In example 2, the washed broth is fed to a first evaporator, transferred to a second evaporator where a recycled stream of GBL is fed to replace the water removed in the first evaporator and heated to remove about 40% more water. The resulting solution is transferred to a third evaporator to remove the remaining water. The resulting slurry contains about 25% by weight P4HB and about 47% by weight of GBL. See [0094]. To increase the purity of the GBL, the slurry is subjected to filtration, which produces a polymer solution containing about 30% P4HB and about 66% GBL. See [0095]. The filtered substantially water-free biomass solution is mixed with standard hydrated lime Ca(OH)2 [calcium hydroxide]. Pyrolysis of the GBL+P4HB+Ca(OH)2 is carried out and condensate is collected. See [0096]. After pyrolysis, the results show that the condensate contains 3% water, 0.06% fatty acids with the balance of material being GBL products. The GBL yield (g of GBL product/g of starting P4HB)x100%) is approximately 87% and the purity of the GBL is about 99%. See [0098]. Thus, the specification provides one working example of a genetically modified E. coli biomass capable of producing P4HB for the production of GBL.
The quantity of experimentation needed to make or use the invention:
In view of the nature of the invention, the breadth of the claims, the guidance and
working examples in the specification, and the level of predictability within the art, as
evidenced above, one skilled in the art could not produce biobased GBL using any and all types of P4HB-containing cells without undue experimentation. Prior to the effective filing date of the instantly claimed invention, it was well known that biobased gamma-butyrolactone can be produced using a genetically engineered E. coli designed to yield P4HB from glucose, as evidenced by Walsem. However, Mitra suggests that researchers continue to develop strategies to realize P4HB synthesis in microbes. Thus, biobased GBL production would be unpredictable in a process that encompasses any P4HB-containg cell.
Accordingly claims 1-8, 10-12, 15 and 17-18 are enabled for a method of producing gamma-butyrolactone (GBL) product from a starting biomass containing water and genetically engineered E. coli cells designed to yield poly-4-hydroxybutyrate (P4HB) from glucose syrup as a carbon feed source, the method comprising: (a) introducing the starting biomass to an evaporator, (b) introducing liquid or vapor GBL to the evaporator as a solvent in a weight equivalent to or less than a weight of water removed to obtain a biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and comprises P4HB dissolved or suspended in the GBL, (c) combining, in a reaction vessel, the biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and a sodium carbonate or calcium hydroxide conversion catalyst and heating the resulting mixture to convert the P4HB to GBL, and (d) collecting the GBL, wherein the liquid or vapor GBL introduced in step (b) is a recycle GBL that is a part of the collected GBL obtained in step (d) and recycled back to the evaporator to be mixed as a solvent with the biomass, wherein the method does not include spray drying and drum drying, wherein the starting biomass is a genetically engineered biomass from a host cell that includes a non-naturally occurring amount of P4HB, and wherein a content of P4HB, and wherein a content of P4HB in the starting biomass is greater than 10% by weight of the total starting biomass.
Response to Arguments
Applicant's arguments filed 04/22/2026 and 06/16/2026 have been fully considered but they are not persuasive.
§112(a) rejection of claims 1-8, 10-12, 15 and 17-18
In the remarks filed 04/22/2026, Applicant argues that the claims are rejected because, per the Examiner, the specification indicates that drying is required in order to heat to 150˚C or higher, but claim 1 recites that no drying step is included, thereby failing to satisfy the enablement requirement. See the remarks the paragraph bridging p. 6-7.
This argument is not persuasive because it is not germane to the enablement rejection. The specification is enabling for the claim limitation that requires “wherein the method does not include spray drying and drum drying” (see claim 1 line 16, and the first paragraph of the rejection above).
In the remarks filed 04/22/2026, Applicant argues that, because the gist of the claimed method resides in the process features, rather than in the selection of cells or catalysts, a person skilled in the art can practice the invention based on the limitations recited in claim 1 without undue experimentation. See the remarks p. 8 paragraph 4. Applicant argues that the gist of the claimed method lies in (i) introducing a recycled GBL vapor or liquid stream into the biomass feed “biomass having a significantly reduced water content” into the evaporator and reactor, and at the same time (ii) by virtue of the significantly reduced water content, eliminating the need to perform “drum drying or spray drying” thereby providing a GBL production method that maximizes energy efficiency. See the remarks, the paragraph spanning p. 7-8. In the remarks filed 06/16/2026, Applicant argues that the technical feature of the invention resides in obtaining a high concentration GBL product through the process features. See the remarks p. 7 paragraph 3.
This argument is not persuasive because Applicant has not pointed to evidence commensurate in scope with the instant claims. Applicant argues that the invention resides in obtaining a high concentration GBL product through the process feature. However, Applicant has not pointed to evidence that reasonably suggests that such GBL product can be obtained using any P4HB-containing cells without undue experimentation. As such, the argument is unpersuasive because arguments of counsel cannot take the place of factually supported objective evidence (MPEP 2145 or 716.01(c)).
In the remarks filed 06/16/2026, Applicant argues that claim 1 defines the minimum P4HB content of the starting biomass so that GBL can be sufficiently produced in the reaction vessel, and makes clear that such content is achieved using genetically engineered biomass comprising a non-naturally occurring amount of P4HB. See the remarks p. 7 paragraph 3.
This argument is not persuasive because it is not commensurate in scope with the instant claims. Claim 1, as amended, requires the content of P4HB in the starting biomass to be greater than 10% by weight of the total starting biomass (last 2 lines). However, claim 1 does not limit the structure of the genetic modification associated with such P4HB cell content. Therefore, the claims encompass any genetically engineered biomass with greater than 10% by weight of the total starting biomass. In example 1, the instant specification teaches fermenting a genetically modified E. coli strain specifically designed for high yield production of P4HB from glucose syrup. The specification discloses that after fermentation, the washed broth contains about 10% by weight of P4HB, 10% by weight of biomass and salts, and 80% by weight of water based on the total weight of the broth. See [0092]. Although the specification states “[t]he content of P4HB in the starting biomass is greater than 10% by weight of the total starting biomass” in paragraph [0017]. The specification does not provide a working example of such starting biomass with greater than 10% P4HB content. Mitra illustrates the unpredictability of genetically modifying cells to arrive at the instantly required P4HB content, because Mitra indicates that researchers are continuously engrossed in developing various strategies to realize P4HB synthesis in microbes (see the first paragraph on page 2 of Mitra).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-5, 7, 11-12, 15, and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over van Harris (US 2015/0183708; as previously relied upon) in view of Samuelson (US 2015/0376152).
Regarding claim 1, Harris teaches poly-3-hydroxypropionate (P3HP) biomass prepared from a genetically engineered E. coli in a fermenter using glucose as the feed. After fermentation, the biomass is either washed using centrifugation or is concentrated directly using a triple effect evaporator. The concentrated broth is then dried using either a spray dryer or a double drum dryer. Alternatively, the unwashed, centrifuged P3HP biomass can be used as the starting material for the thermolysis reactor. See [0147]. Harris discloses that thermolysis, heating and pyrolysis are synonyms. See [0076]. Harris teaches adding heat transfer fluid to washed, dried and ground biomass in order to facilitate conversion during pyrolysis. Heat transfer fluids include gamma-butyrolactone. See [0162]. Harris teaches creating a slurry or a suspension of biomass +catalyst in the heat transfer fluid and pyrolyzing the mixture. See [0163]. Harris teaches evaluating catalysts including calcium hydroxide. Harris discloses that the final concentration of catalyst in the dried P3HP biomass samples is 2-5% by weight dry biomass while the final water content was <3% by weight dry biomass, which is 5 wt% or less water as instantly required. See [0133]. Furthermore, Harris teaches heating a biomass to reduce water content to about 5 wt% or less. See claim 19 of Harris. For pyrolysis, Harris teaches feeding dry or wet biomass+ catalyst to a Fast Acting Selective Thermolysis FAST™ reactor (i.e. reaction vessel). See [0148]. After pyrolysis the biomass suspension remaining is filtered and the heat transfer fluid is recovered to be used in subsequent pyrolysis runs. See [0163]. As such, the heat transfer fluid can be recycled. See [0026]. The wt% of heat transfer fluid can be 10 wt% based on the weight of the P3HP biomass. See [0080]. Heat transfer fluid that boils at pyrolysis temperature is vaporized, recovered (i.e. collected) and then added back to the biomass. See [0017]. Volatile heat transfer fluids include GBL. See [0162].
Harris does not teach producing GBL product from a starting biomass containing water and poly-4-hydroxybutyrate containing cells.
Harris does not teach a content of P4HB in the starting biomass that is greater than 10% by weight of the total starting biomass.
Samuelson teaches biorefinery processes for the production of biobased chemicals including gamma-butyrolactone (GBL) and acrylic acid. See [0003]. Samuleson teaches producing biobased chemicals starting with genetically engineered microbes metabolizing glucose to produce polyhydroxyalkanoate polymers such as poly-3-hydroxypropionate (P3HP) or poly-4-hydroxybutyrate (P4HB). See [0004]. Samuelson discloses that the level of PHA in the starting biomass should be greater than 10% by weight of the total biomass (i.e. P4HB content greater than 10% by wt). See [0011]. In example 2, Samuelson teaches producing biobased gamma-butyrolactone (GBL) from whole fermentation broth which contains biomass with poly-4-hydroxybutyrate (P4HB) polymer and water (i.e. starting biomass). The P4HB polymer is first solvent extracted and then the solution thermolyzed under vacuum. See [0076]. Samuelson teaches combining P4HB containing fermentation broth with Ca(OH)2 and heating. Samuelson discloses that the P4HB polymer thermally degrades to produce GBL vapor. GBL is condensed and collected. See [0077].
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to substitute Samuelson’s starting biomass comprising water and P4HB for Harris’s P3HP biomass. One of ordinary skill in the art would have been motivated to do so because Samuelson suggests that biomasses producing P3HP are interchangeable with biomasses producing P4HB. There would have been a reasonable expectation of success because Harris and Samuelson both teach processes in which biomass is combined with a Ca(OH)2 catalyst and heated such that GBL vaporizes and can be collected.
Harris and Samuelson do not teach introducing liquid or vapor GBL to the evaporator as a solvent in a weight equivalent to or less than a weight of water removed to obtain a biomass suspension or solution that contains 5 wt% or less of water based on the weight of the biomass suspension or solution and comprises P4HB dissolved or suspended in the GBL.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to combine Samuelson’s starting biomass with Harris’s recycled GBL heat transfer fluid prior to heating in the triple-effect evaporator, and to further optimize the amount of GBL heat transfer fluid introduced. One of ordinary skill in the art would have been motivated to combine Samuelson’s starting biomass with GBL prior to heating in the triple-effect evaporator of Harris, because Harris suggests that biomass, with or without a catalyst, can be combined with a processing fluid or heat transfer fluid prior to heating in order to increase the efficiency of the heat transferred from an external heating source. See [0099] of Harris. There would have been a reasonable expectation of success because Harris teaches combining biomass with a GBL heat transfer fluid prior to heating (see e.g. [0026]), and Harris teaches introducing biomass into an evaporator. One of ordinary skill in the art would have been further motivated to optimize the amount of GBL introduced, because Harris suggests introducing GBL at a weight that is 10wt% based on the weight of the biomass; and Harris suggests obtaining a biomass suspension that contains 5% or less of water based on the weight of the biomass. There would have been a reasonable expectation of success because Harris teaches a 10wt% starting point from which one of ordinary skill in the art could have reasonably optimized. MPEP 2144.05(II)(A) states that “[w]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Harris and Samuelson do not explicitly teach a method that does not include spray drying and drum drying.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention that spray drying and drum drying are unnecessary, because Harris suggests that unwashed and centrifuged biomass can be used as the starting material for a thermolysis reactor as an alternative to a spray dryer or a double drum dryer. See [00147] of Harris.
Claim interpretation: claim 2 requires mixing, stirring, vortexing or agitation for the intended purpose of promoting extraction of P4HB from host cells into GBL. As such, any mixing, stirring, vortexing or agitation of the required host cell meets the instant claim limitation.
Regarding claim 2, Harris teaches generating biomass and washing by centrifuging (i.e. vortexing) the biomass. See [0127].
Samuelson teaches fermenting E. coli biomass containing P4HB. The fermentation broth is pH adjusted by the addition of Ca(OH)2 and added to a centrifuge flask. The contents of the centrifuge flask are homogenized using a mixer. The centrifuge flask is then spun down (i.e. vortexed). See [0077].
Therefore, Harris and Samuelson teach step (e) vortexing host cells.
Regarding claim 3, Harris teaches centrifuging biomass. Harris teaches repeating a centrifugation process three times in order to remove any of the dissolved salts (i.e. solid) from the fermentation media prior to pyrolysis. See [0127].
Regarding claim 4, Harris, in example 5, teaches concentrating biomass directly using a triple effect evaporator. Harris suggests that unwashed and centrifuged biomass can be used as the starting material for the thermolysis reactor. See [0147]. Harris teaches feeding dry biomass and catalyst to a FAST reactor [for thermolysis]. See [0148]. Harris teaches adding the catalyst directly after fermentation of the biomass and then drying the biomass+catalyst. See [0072]. For pyrolysis, Harris suggests that inert gases such as carbon dioxide or nitrogen can be added to assist in moving organic vapors. See [0148]. Vapor steam exits reactor into a fractional condensation column to remove water. See [0150] and figure 7. Furthermore, Harris teaches adding heat transfer fluid, such as GBL, prior to heating. See [0026]. Therefore, Harris teaches removing water not adding water, which meets the instant requirement.
Regarding claim 5, Harris teaches concentrating biomass using a triple effect evaporator (i.e. multiple serial evaporators in fluid communication with each other). See [0147]. Harris teaches adding heat transfer fluid prior to heating. Heat transfer fluid includes gamma-butyrolactone (GBL). In certain embodiments, the heat transfer remains with the biomass and can be recycled. See [0026]. The heat transfer fluid itself once isolated from the condensate can also be purified, dried and then used in subsequent pyrolysis runs. See [0162].
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to combine Samuelson’s starting biomass with Harris’s recycled GBL heat transfer fluid prior to heating in the triple-effect evaporator, as discussed above, and in the process the recycled GBL would necessarily be introduced to one of the evaporators within the triple effect evaporator.
Claim Interpretation: instant claim 7 requires step (a) to either be carried out at atmospheric pressure, or step (a) can be carried out under vacuum at 60˚C -100˚C.
Regarding claim 7, Harris teaches heating done in a vacuum at atmospheric pressure. See [0078].
Regarding claim 11, Harris teaches concentrating biomass after fermentation using a triple effect evaporator. See [0148]. Harris teaches heating for a time period from about 30 seconds to about 5 minutes or from about 5 minutes to about 2 hours. See claim 22 of Harris.
Harris and Samuelson do not teach carrying out step (a) [introducing the starting biomass to an evaporator] for a period of time from 5 minutes to 2 hours.
I It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to optimize the evaporation time based on Harris’s suggestion. A person of ordinary skill in the art has good reason to pursue the known options within their technical grasp. There would have been a reasonable expectation of success because Harris teaches introducing biomass to a triple effect evaporator, and Harris teaches a heating time from about 5 minutes to about 2 hours, which overlaps with the instantly claimed from 5 minutes to 2 hours. MPEP 2144.05(II)(A) states that “[w]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 12, Samuelson teaches a biobased gamma-butyrolactone product when the biomass comprises poly-4-hydroxybutyrate, and a biobased acrylic acid product when the biomass comprises a poly-3-hydroxypropionate. See claim 2 of Samuelson. Samuelson discloses that the gamma-butyrolactone product comprises less than 0.1% by weight of side products. See claim 43 of Samuelson. Samuelson teaches the gamma-butyrolactone product may contain 99% by weight gamma-butyrolactone and 1% by weight side products. See [0058].
Regarding claim 15, Samuelson teaches a product yield that is about 76% by weight or greater based on one gram of a gamma-butyrolactone in the product per gram of poly-4- hydroxybutyrate. See claim 42 of Samuelson. In certain embodiments, a yield of biobased chemical product is about 85% by weight or greater based on one gram of a product per gram of the polyhydroxyalkanoate. See [0017].
Regarding claim 17-18, Samuelson teaches a biobased gamma-butyrolactone product when the biomass comprises poly-4-hydroxybutyrate, and a biobased acrylic acid product when the biomass comprises a poly-3-hydroxypropionate. See claim 2 of Samuelson. Samuelson discloses that the gamma-butyrolactone product comprises less than 0.1% by weight of side products. See claim 43 of Samuelson. Samuelson teaches the gamma-butyrolactone product may contain 99% by weight gamma-butyrolactone and 1% by weight side products. See [0058].
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to substitute Samuelson’s starting biomass with P4HB and water for Harris’s P3HP biomass, as discussed above, and in the process arrive at a GBL product that comprises less than 5% by weight of side products.
Claims 6, 8 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over van Harris (US 2015/0183708; as previously relied upon) and Samuelson (US 2015/0376152), as applied to claims 1-5, 7, 11-12, 15, and 17-18 above, and further in view of Clark (US 2011/0003355, as previously relied upon).
Regarding claim 6, Harris teaches concentrating biomass using a triple effect evaporator. See [0147]. Furthermore, Harris teaches adding heat transfer fluid prior to heating. Heat transfer fluid includes gamma-butyrolactone (GBL). The heat transfer fluid can be recycled. See [0026].
Harris and Samuelson do not teach recycle GBL that is introduced into the second evaporator and/or the third evaporator.
Clark teaches developing processes for the isolation of water miscible compounds that have boiling points higher than water from microbial fermentations, while bearing in mind the environmental and cost benefit of recycling other fermentation components. See [0008]. Clark teaches compounds of interest with boiling points higher than water including GBL. See [0033]. Clark teaches a triple-effect evaporator system that can be used to separate water from a product of interest. See [100]. Effects are numbered beginning with the one heated by steam, Effect I. Vapor from effect I is used to heat Effect II, which consequently operates at lower pressure. This continues through each addition effect. See [0103]. Clark teaches a backward feed arrangement that uses III, II, and I. Clark suggests that such configuration is more efficient than forward feed configuration as the feed is gradually heated. This arrangement also reduces the viscosity differences through the system and is thus useful for viscous fermentation broths. Furthermore, Clark teaches a mixed feed arrangement with the feed entering the middle of the system, or effects II, III, and I. The final evaporation is performed at the highest temperature. See [0105].
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to arrange Harris’s triple effect evaporator based on Clark’s teachings and suggestions. One of ordinary skill in the art would have been motivated to arrange Harris’s triple effect evaporator into the backward feed arrangement or the mixed feed arrangement taught by Clark, because Clark suggests that the backward feed is more efficient than a forward feed and can reduce viscosity differences in viscous fermentation broths; and Clark suggests that the mixed feed arrangement allows for the final evaporation to be performed at the highest temperature (see [0105]). There would have been a reasonable expectation of success because Harris teaches concentrating biomass in a triple effect evaporator (see [0147]), and Clark teaches triple effect evaporator arrangements that are useful for isolating compounds of interest, such as GBL.
Regarding claim 8, Clark teaches removing a portion of water in any amount including 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80%, and all values in between. See [0099]. Clark discloses in a multiple effect arrangement, the latent heat of the vapor product off of an effect is used to heat the following effect. See [103].
Harris, Samuelson and Clark do not teach removing 20-50% of water contained in the starting biomass in the first evaporator, removing 20-45% of water contained in the starting biomass in the second evaporator, and removing 5-35% water contained in the starting biomass in the third evaporator.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to optimize the portion of water removed in each evaporator of Harris’s triple effect evaporator based on Clark’s suggestion. One of ordinary skill in the art would have been motivated to do so because Clark suggests that the vapor product of the first effect impacts the heating of the following effect (see [0103]). There would have been a reasonable expectation of success because Clark teaches removing a portion of water in any amount. MPEP 2144.05(II) “[w]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 10, Harris teaches concentrating biomass using a triple effect evaporator. See [0147].
Samuelson discloses that heating of solvent+P4HB phase under vacuum will produce GBL by a thermal unzipping reaction of the polymer chain in solution. The thermal unzipping reaction at a temperature 50°C - 190°C. See [0029].
Harris and Samuelson do not teach carrying out step (a) [introducing the starting biomass to an evaporator] at a temperature from 70-90˚C under vacuum.
Clark teaches an evaporator system comprising one or more effects. See claim 9 of Clark. The evaporator system comprises a double- or triple-effect evaporator. See claim 10 of Clark. The evaporator system comprises a vacuum. See claim 14 of Clark.
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to substitute Clark’s vacuum triple-effect evaporator for Harris’s triple effect evaporator, and to further adjust the temperature of the evaporator based on Samuelson’s suggestion. One of ordinary skill in the art would have been motivated to use Clark’s vacuum triple-effect evaporator, because Clark suggests that the vacuum triple-effect evaporator can be used in processes for isolating compounds of interest from microbial fermentation (see [0008]), and Clark teaches compounds of interest including GBL (see [0033]). There would have been a reasonable expectation of success because Harris teaches concentrating biomass in a triple effect evaporator, and Clark teaches a vacuum triple-effect evaporator and suggests that it can be used with microbial fermentation biomass. One of ordinary skill in the art would have been further motivated to adjust the temperature of the vacuum triple-effect evaporator, because Samuelson suggests that P4HB can be thermally unzipped to produce GBL at a temperature 50°C - 190°C (see [0029]). There would have been a reasonable expectation of success because Samuelson’s 50°C- 190°C temperature range overlaps with the instantly required 70°C - 90°C. MPEP 2144.05(II)(A) indicates that differences in concentration or temperature generally amount to “routine optimization” and will not support patentability unless there is evidence indicating the claimed feature is critical. “Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Response to Arguments
Applicant's arguments filed 04/22/2026 and 06/26/2026 have been fully considered but they do not apply to the new grounds for rejection set forth above.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-8, 10-12, 14-15 and 17-18 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1-28 of U.S. Patent No. 9,084,467 (as cited in the IDS filed 03/28/2023) in view of Harris (US 2015/0183708; as previously relied upon) and Samuelson (US 2015/0376152), and Clark (US 2011/0003355, as previously relied upon).
Patent claim 1 recites a process for production of a biobased gamma-butyrolactone product, comprising
a) combining a genetically engineered biomass comprising poly-4-hydroxybutyrate and a catalyst; and
b) heating the biomass with the catalyst to convert the poly 4-hydroxybutyrate to a gamma-butyrolactone product, wherein the catalyst is sodium carbonate or calcium hydroxide.
Patent claim 4 recites the process of claim 1, wherein the process further includes an initial step of culturing a recombinant host with a renewable feedstock to produce a poly-4-hydroxybutyrate biomass.
Patent claim 12 recites the process of claim 1, wherein heating reduces the water content of the biomass to about 5 wt %, or less.
Patent claim 13 recites the process of claim 1, wherein the heating temperature is from about 200° C. to about 350° C
Patent claim 16 recites process of claim 1, wherein the heating is for a time period from about 5 minutes to about 2 hours.
Patent claim 17 recites the process of claim 1, further comprising recovering the gamma-butyrolactone product.
Patent claim 27 recites the product of claim 26, wherein the gamma-butyrolactone product comprises less than 5% by weight of side products.
Patent claim 28 recites a poly-4-hydroxybutyrate biomass produced from renewable resources which is suitable as a feedstock for producing gamma-butyrolactone product, wherein the level of poly-4-hydroxybutyrate in the biomass is greater than 50% by weight of the biomass.
Patent claim 30 recites the process of claim 1, wherein product is about 85% by weight or greater based on one gram of a gamma-butyrolactone in the product per gram of poly-4-hydroxybutyrate.
The patent claims lack (a) introducing the starting biomass to an evaporator; (b) introducing liquid or vapor GBL to the evaporator as a solvent in a weight equivalent to or less than a weight of water removed to obtain a biomass suspension or solution that contains 5 wt% or less water and comprises P4HB dissolved or suspended in the GBL; (c) combining, in a reaction vessel; (d) liquid or vapor GBL introduced in step (b) is a recycle GBL that is a part of the collected GBL obtained in step (d) and recycled back to the evaporator to be mixed as a solvent with the biomass, wherein the method does not include drum drying and spray drying (relevant to instant claim 1). The patent claims lack step (e) mixing, stirring, vortex, or agitation to promote extraction of P4HB from host cells into GBL (relevant to instant claim 2). The patent claims lack step (f) removing solids from the biomass suspension or solution that is substantially free of water, by filtration, precipitation, or centrifugation (relevant to instant claim 3). The patent claims lack no water is added in steps (a), (b), and (c) (relevant to instant claim 4). The patent claims lack an evaporator that comprises multiple serial evaporators that are in fluid communication with each other and the recycle GBL is introduced to one or more of the evaporators (relevant to instant claim 5). The patent claims lack an evaporator contains a first evaporator, a second evaporator, and a third evaporator, which are in fluid communication with each other in serial in this order, and the recycle GBL is introduced into the second evaporator and/or the third evaporator (relevant to instant claim 6). The patent claims of Walsem ‘467 lack a temperature of from 60° C - 100° C under vacuum or at atmospheric pressure (relevant to instant claim 7). The patent claims lack 20-50% of water contained in the starting biomass is removed in the first evaporator, 20-45% of water contained in the starting biomass is removed in the second evaporator, and 5-35% water contained in the starting biomass is removed in the third evaporator; and wherein the recycled GBL is introduced to replace the water removed from the first and the second evaporator (relevant to instant claim 8). The patent claims lack a step (a) that is carried out at a temperature from 70° C - 90° C under vacuum (relevant to instant claim 10).
Harris teaches biomass concentrated directly using a triple effect evaporator. The concentrated broth is then dried using either a spray dryer or a double drum dryer. Alternatively, the unwashed, centrifuged P3HP biomass can be used as the starting material for the thermolysis reactor. See [0147]. Harris teaches a GBL heat transfer fluid that can be recycled. See [0026]. The wt% of heat transfer fluid can be 10 wt% based on the weight of the P3HP biomass. See [0080]. Furthermore, Harris teaches feeding biomass+catalyst into a reactor. See [0148]. Harris teaches the catalyst calcium hydroxide. See [0133] (relevant to instant claim 1). Harris teaches generating biomass and washing by centrifuging (i.e. vortexing) the biomass. See [0127] (relevant to instant claims 2-3). Harris suggests removing water, see e.g. [0150], such that Harris does not teach adding water (relevant to instant claim 4). Harris teaches a triple effect evaporator, which includes multiple serial evaporators in fluid communication with each other. See [0147] (relevant to instant claim 5). Clark teaches a backward feed arrangement that uses effects III, II, and I. Clark suggests that such configuration is more efficient than forward feed configuration. See [0105] (relevant to instant claim 6). Harris teaches heating done in a vacuum at atmospheric pressure. See [0078] (relevant to instant claim 7). Clark teaches removing a portion of water in any amount including 20%, 50%, and all values in between. See [0099] (relevant to instant claim 8). Samuelson suggests that P4HB under vacuum will produce GBL at a temperature of 50°C - 190°C. See [0029]. Clark teaches an evaporator system comprises a vacuum. See claim 14 of Clark (relevant to instant claim 10).
It would have been obvious to a person of ordinary skill in the art prior to the effective filing date of the instantly claimed invention to substitute the genetically engineered biomass recited in patent claim 1, for Harris’s starting biomass; to substitute Clark’s vacuum backwards feed triple effect evaporator for Harris’s triple effect evaporator; and to further optimize the evaporation temperature based on Samuelson’s suggestion, and optimize the water removal in order to produce GBL.
Response to Arguments
Applicant's arguments filed 04/22/2026 and 06/16/2026 have been fully considered but they do not apply to the new grounds for rejection set forth above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KIMBERLY C BREEN whose telephone number is (571)272-0980. The examiner can normally be reached M-Th 7:30-4:30, F 8:30-1:30 (EDT/EST).
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/K.C.B./Examiner, Art Unit 1657
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